In this study, pilot-scale experiments for the removal of nitrogen from sewage obtained from a county Y sewer system were performed using modified A(2)O processes. Using this approach, the total amount of nitrogen discharged during denitrification of the influent was average 38.6 mg/L and a level of average 10.8 mg/L was maintained throughout the denitrification process, which resulted in an average removal efficiency that was greater than 72%. The nitrogen components in the effluent water consisted of 22% ammonia nitrogen, 6% nitrite nitrogen and 72% nitrate nitrogen, reaching a nitrification efficiency of 94%. In conclusion, since these advanced treatment methods, which involve modified A(2)O processes, were successfully employed to remove nitrogen from sewage discharge, they hold promise for wide spread use by treatment plants.